Silicate filled polyolefin resin composites

Abstract

Silicate filled polyolefin resin composites exhibit improved mechanical properties if the silicate filler and polyolefin resin are specially combined with additives comprising chlorinated aliphatic compounds. The composites are preferably made from blends comprising about 1-36 parts by weight silicate flakes or fibers, 9 parts by weight propylene resin and minor effective amounts of the additive. Various processing techniques such as selecting the time the blends reside at melt temperatures during compounding permits development of advantageous properties.

What is claimed is: 
     
       1. A composite made by a process which comprises: A. providing a blend consisting essentially of melt forming resin made from monomers comprising olefinic hydrocarbon monomers, a silane free or substantially silane free silicate and a strengthening amount of an additive that is a minor amount by weight of the resin and silicate, the additive consisting essentially of one or more chlorinated hydrocarbons having a molecular weight of about 250-10,000 and about 60-80% by weight chlorine;   B. maintaining said blend as a melt at a temperature in a range between 170°-300° C. for a time sufficient to strengthen the composite; and   C. subsequently passing said blend to a cooling zone, directly or indirectly, and cooling said blend, being free of silane or substantially free of silane, to below said melt temperature.   
     
     
       2. A composite made according to claim 1, wherein the resin comprises one or more selected from the group consisting of polyethylene, polypropylene, copolymers comprising ethylene, propylene and mixtures thereof. 
     
     
       3. A composite made according to claim 1, wherein the resin comprises polypropylene. 
     
     
       4. A composite made according to claim 1, wherein the silicate comprises glass fibers or flakes. 
     
     
       5. A composite made according to claim 1, wherein the silicate comprises talc. 
     
     
       6. A composite made according to claim 5, wherein the molecular weight of the chlorinated aliphatic hydrocarbons is in a range of about 800-5,000. 
     
     
       7. A composite made according to claim 5, wherein the additive comprises resinous chlorinated paraffin wax having about 60-80% chloride by weight. 
     
     
       8. A composite made according to claim 7, wherein the resin comprises one or more selected from the group consisting of polyethylene, polypropylene, copolymers comprising propylene, ethylene and mixtures thereof. 
     
     
       9. A composite made according to claim 8, wherein the resin comprises polypropylene. 
     
     
       10. A composite made according to claim 9, wherein the additive comprises from about 0.2-3% by weight of the combined weight of the silicate and resin. 
     
     
       11. A composite made according to claim 10, wherein the weight ratio of mica filler to resin is about 5:2-2:5 and the melt is maintained for at least about five minutes at a temperature of at least about 170° C. 
     
     
       12. A composite made in accordance with claim 1, wherein the silicate has been combined with the additive to provide a coating on at least a portion of the silicate particles. 
     
     
       13. A composite according to claim 12, wherein the additive comprises a resinous chlorinated hydrocarbon having between about 60-80% by weight chlorine. 
     
     
       14. A composite according to claim 13, wherein the silicate and the resinous chlorinated hydrocarbon having between about 60-80% by weight chlorine are combined by heating at a temperature above the melting temperature of the resinous chlorinated hydrocarbon to provide a coating on at least a portion of the silicate particles and the resin comprises polypropylene. 
     
     
       15. A composite according to claim 14, wherein the silicate and additive comprising one or more chlorinated aliphatic compounds are combined at a temperature above the melting temperature of the additive. 
     
     
       16. A composite made by a process which comprises: A. providing a blend consisting essentially of melt forming resin made from monomers comprising olefinic hydrocarbon monomers, a silane free or substantially silane free silicate and a strengthening amount of an additive that is a minor amount by weight of the resin and silicate, the additive consisting essentially of one or more chlorinated aliphatic hydrocarbons having a molecular weight of about 250-10,000 and about 60-80% by weight chlorine wherein the silicate is combined with the additive to provide a coating on the silicate particles;   B. maintaining said blend as a melt at a temperature in a range between 170°-300° C. for a time sufficient to strengthen the composite; and   C. subsequently passing said blend to a cooling zone, directly or indirectly, and cooling said blend, being free of silane or substantially free of silane, to below said melt temperature.   
     
     
       17. A composite made according to claim 16, wherein the chlorinated aliphatic hydrocarbons comprise resinous chlorinated paraffin wax having a molecular weight between about 800-5,000 and about 60-80% by weight chlorine. 
     
     
       18. A composition made according to claim 17, wherein the additive comprises up to about 13% by weight of the silicate. 
     
     
       19. A composite made according to claim 18, wherein the weight ratio of silicate to resin is about 5:2-2:5. 
     
     
       20. A process for making a composite which comprises: A. providing a blend consisting essentially of melt forming resin made from monomers comprising olefinic hydrocarbon monomers, a silane free or substantially silane free silicate and a strengthening amount of an additive that is a minor amount by weight of the resin and silicate, and additive consisting essentially of one or more chlorinated aliphatic hydrocarbons having a molecular weight between about 250-10,000 and about 60-80% by weight chlorine;   B. maintaining said blend as a melt at a temperature in a range between 170°-300° C. for a time sufficient to strengthen the composite; and   C. subsequently passing said blend to a cooling zone, directly or indirectly, and cooling said blend, being free of silane or substantially free of silane, to below said melt temperature.   
     
     
       21. A process according to claim 20, wherein the resin comprises one or more selected from the group consisting of polyethylene, polypropylene, copolymers comprising ethylene, propylene and mixtures thereof. 
     
     
       22. A process according to claim 20, wherein the resin comprises polypropylene. 
     
     
       23. A process according to claim 20, wherein the silicate comprises glass fibers or flakes. 
     
     
       24. A process according to claim 20, wherein the silicate comprises talc. 
     
     
       25. A process according to claim 20, wherein the molecular weight of the chlorinated aliphatic hydrocarbons is in a range of about 800-5,000. 
     
     
       26. A process according to claim 24, wherein the additive comprises resinous chlorinated paraffin wax having about 60-80% chloride by weight. 
     
     
       27. A process according to claim 26, wherein the resin comprises one or more selected from the group consisting of polyethylene, polypropylene, copolymers comprising propylene, ethylene and mixtures thereof. 
     
     
       28. A process according to claim 27, wherein the resin comprises polypropylene. 
     
     
       29. A process according to claim 28, wherein the additive comprises from about 0.2-3% by weight of the combined weight of the silicate and resin. 
     
     
       30. A process according to claim 29, wherein the weight ratio of silicate to resin is about 5:2-2:5 and the melt is maintained for at least about five minutes at a temperature of at least about 170° C. 
     
     
       31. A process according to claim 20, which comprises conjoining the resin with silicate that has been combined with the additive to provide a coating on at least a portion of the silicate particles. 
     
     
       32. A process according to claim 31, wherein the additive comprises a resinous chlorinated hydrocarbon having between about 60-80% by weight chlorine. 
     
     
       33. A process according to claim 32, wherein the silicate and the resinous chlorinated hydrocarbon having between about 60-80% by weight chlorine are combined by heating at a temperature above the melting temperature of the resinous chlorinated hydrocarbon to provide a coating on at least a portion of the silicate particles and the resin comprises polypropylene. 
     
     
       34. A process according to claim 33, wherein the silicate and additive comprising one or more chlorinated aliphatic compounds are combined at a temperature above the melting temperature of the additive. 
     
     
       35. A process for making a composite, which comprises: A. providing a blend consisting essentially of melt forming resin made from monomers comprising olfinic hydrocarbon monomers, a silane free or substantially silane free silicate, a strengthening amount of an additive that is a minor amount by weight of the resin and silicate, the additive consisting essentially of one or more chlorinated aliphatic hydrocarbons having a molecular weight of about 250-10,000 and about 60-80% by weight chlorine and wherein the silicate is combined with the additive to provide a coating on the silicate;   B. maintaining said blend as a melt at a temperature in a range between 170°-300° C. for a time sufficient to strengthen the composite; and   C. subsequently passing said blend to a cooling zone, directly or indirectly, and cooling said blend, being free of silane or substantially free of silane, to below said melt temperature.   
     
     
       36. A process according to claim 35, wherein the chlorinated aliphatic hydrocarbons comprise resinous chlorinated parrafin wax having a molecular weight between about 800-5,000 and about 60-80% by weight chlorine. 
     
     
       37. A process according to claim 36, wherein the additive comprises up to about 15% by weight of the silicate. 
     
     
       38. A process according to claim 37, wherein the weight ratio of silicate to resin is about 5:2-2:5.